The Minimum Capital Required / Starting Unit Size is not the same as the Model Account Starting Equity.
The starting account equity is the amount of capital that a developer started his system with. This is different than the “minimum amount required to trade.”
Example: You can start a system with a billion dollars, but if you only trade one share of AAPL at a time, your “minimum starting size” might be $1,000.
The numbers mean different things.
A developer can decide how much to start his system with.
C2 decides what the minimum “starting unit” size is based on your trade history. They are different.
Why does C2 list a different starting size?
You see, C2 analyzes your trade history, and it sees that you bought (for example) 5 contracts .
However, it also sees that you bought the five together as a unit, and then sold them together as a unit. In other words, you did not "leg in" or "leg out" of the trade.
This means that an Autotrader could very nicely set his scaling size to (for example) 20%, and thus only trade one contract at a time.
If your trade style ever changes (i.e. if you buy 3, then sell 2, then buy 1, then sell 2 for example), C2 will automatically recognize that your style no longer allows for "clean" scaling-down for AutoTraders, and the "minimum unit size" will automatically change.